The Ultimate Gas Logs Buying Guide [2020]


Gas appliances represent 80% of the hearth products installed today. Rightfully so, since today’s gas logs look exactly like real wood logs, but require much less maintenance. You won’t have to load fuel, tend the fire, or remove ashes. 

Gas logs are the “original” gas hearth appliance since becoming a part of the hearth industry way back in the ‘50s. Back then, they had an unrealistic blue flame and lacked the realism that real fires had. Today’s gas logs look and feel exactly like wood burning. 

If you’re not a fan of the wood-burning look, you can always utilize a more “modern look.” We’ve seen sets that use other materials like cut glass, pine cones, acorns, rocks, and cannonballs(!) to give unique looks to the fireplaces. 

If you have a wood stove, or you’re wanting to build a fireplace, and you’re looking at gas appliances, then you’re in the right place.

Measure BTU when Choosing Gas Logs

British Thermal Units (BTU) measure heating power. Before you can determine the BTUs needed, you’ll need to know the size of the room you’re heating. We’ve made these charts to help you decide what you need.

BTUs Needed to Heat a Room with an 8-ft Ceiling

12-ft Length18-ft Length24-ft Length30-ft Length36-ft Length
12-ft Width5,18847,77610,36812,96015,552
18-ft Width7,77611,66415,55219,44023,328
24-ft Width10,36815,55220,73625,92031,104
30-ft Width12,96019,44025,92032,40038,880
36-ft Width15,55223,33831,10438,88046,556

BTUs Needed to Heat a Room with an 8-ft Ceiling

12-ft Length18-ft Length24-ft Length30-ft Length36-ft Length
12-ft Width6,4809,72012,96016,20019,400
18-ft Width9,72014,58019,40024,30029,160
24-ft Width12,96019,44025,92032,40038,800
30-ft Width16,20024,30032,40040,50045,600
36-ft Width19,44029,16038,88048,60058,320

Pick Your Gas

Gas log sets are designed to run on either natural gas or propane. You may already have a gas line running to your home. In this case, the gas you burn should be what you already have. But if you don’t we’ll dive into each to help you determine the best fit. 

Natural Gas

Since pipelines deliver natural gas, it is more common in cities. Today’s natural gas suppliers deliver fuel that contains about 1,000 BTUs per cubic foot. 


  • Usually less expensive than propane gas logs
  • Lighter than air (0.65 specific gravity), so it dissipates into the atmosphere after combustion


  • Needs to be hard-piped to any appliance from buried gas service lines
  • Natural gas service may not be available in your area

Liquid Propane

Propane has been around as a heating source since the very early 1900s. It is more common than natural gas in many rural parts of the United States and very popular for heating and cooking.


  • Contains more carbon dioxide than natural gas
  • Burns three times hotter than natural gas
  • Can be operated independently of natural gas lines or appliances
  • Popular in rural areas since it can be used in areas where natural gas service is not


  • More expensive than natural gas
  • Requires installation of a dedicated tank
  • Often requires you to sign a contract with a propane dealer to refill your tank

Know Your Venting Options

When shopping for gas logs, you need to know whether to choose vented or vent-free logs. There are many different factors that contribute to this decision, such as looks vs. efficiency, local building codes, and even fireplace placement. 


If you are wanting to convert your wood-burning fireplace, then it is probably easier to get a vented gas log set. This is because vented gas log sets are made to be used in existing wood-burning fireplaces with a fully operational chimney. 

Vented gas logs must be used with a functional chimney. They also require the damper to stay open at all times to prevent the build-up of carbon monoxide and other dangerous combustion byproducts. 

Burners for vented logs will come as either Standard or American National Standards Institute (ANSI) certified. If you buy a standard burner, then it is assembled after you receive it. If you receive an ANSI certified burner, then it is already assembled and tested for safety. Certain cities may require you to buy ANSI certified burners, so you should check with your city before buying a gas log set. 


  • Full, natural flame appearance
  • Higher flame
  • No BTU limit
  • Expansive ember bed helps create a more realistic look
  • Flames can touch the logs
  • Logs can be rearranged to fit however you think looks best


  • Only about 10% efficient
  • Requires venting and the use of a damper clamp
  • Your damper must stay open at all times


Vent-free or ventless gas logs don’t require a chimney or vent to operate. They are designed to burn at nearly 100% efficiency with a clean, smokeless flame. What does remain is water vapor and carbon dioxide. If carbon monoxide or other toxic gases remain it will be very minimal and nothing to worry about. 

Just like with the older gas sets, the flames are blue and much smaller than the flames created by vented sets. You can still get a realistic flame, but the flames aren’t as big as the vented sets can provide. 

Since water vapor and carbon dioxide are what’s left while burning you may notice an excessive amount of condensation on your windows and throughout the room. Too much moisture can contribute to mold growth, which can lead to much larger problems. 

Any of the following symptoms could point to a venting system problem: 

  • Damp patches on interior walls or exterior walls
  • Peeling wallpaper
  • Blistered paint
  • Stains on the ceiling around the chimney
  • White stains on the outside of the masonry chimney (we call that efflorescence)
  • Eroded mortar joints
  • Crumbling bricks

Also, since it’s not vented, and the combustion air isn’t able to escape through a chimney, your vent free gas log set could leave an odor when burning. 

Ventless gas logs are required to be ANSI certified and cannot be modified in any way once you get them. 

Your vent-free gas logs need to be stacked around the gas outlets on the burner to prevent flames from coming into contact with the logs. If the flames do touch the logs, then carbon monoxide could be produced. Because of this, some states, like California, have outlawed ventless appliances for indoor use. 

The BTUs of ventless appliances are limited to a maximum of 40,000 BTUs per hour to help maintain adequate oxygen levels in the room. This level can be much smaller, to around 6,000 BTUs per hour, depending on the size of the room.


  • Nearly 100% efficient
  • More heat is produced and introduced to your home
  • Less gas consumption
  • No venting is required
  • Equipped with an Oxygen Depletion Sensor (ODS)
  • All burners are ANSI certified, tested, and factory assembled


  • Blue, unnatural, and unattractive flame appearance
  • 6,000 – 40,000 BTU limit (depending on the room)
  • Burners cannot be modified and logs cannot be rearranged. 
  • More restrictions restrictions
  • Sometimes produces an odor while burning
  • Increases the humidity levels in your home
  • Can cause lung irritation if you have allergies or lung conditions

Determine the Size of Your Gas Logs

To get the exact look that you’re going for, it’s important for you to choose the right sized logs set that fits in your fireplace. Sizing for the gas logs is determined by the manufacturer. You should always check the sizing requirements and recommended clearances before purchasing your gas log set to make  sure you get the right size. 

When your gas logs aren’t the right size, it can overheat your firebox and gas valves, causing permanent damage to your log set, fireplace, and home. Luckily finding the right size is actually a pretty easy process. All you’ll need to do is measure the front width, rear width, depth, and height of your firebox. 

Follow these steps:

  1. Measure the front width of your fireplace
  2. Measure the width at the back of your fireplace
  3. Measure the depth from the front to the back of your fireplace
  4. Measure the height from top to bottom at the front of your fireplace
  5. Measure the height from top to bottom at the back of your fireplace

How Do You Want to Start & Control Your Gas Fire? 

This is a pretty important decision to make too. Do you want to worry about using a match to light your flame? Or are you more about showmanship and would prefer a remote? Or do you want to keep it simple enough by just operating a manual safety pilot? 

Match Light

Unfortunately, this one is only for natural gas. There is no pilot; only your logs and a burner. You light your fire just as it sounds: by placing a match or lighter near the burner, then turning on the gas with your key valve. You can control the flame height with your key valve, which you can normally find on the outside of the fireplace on the wall or on the floor. Match lights are usually the most affordable and simplest control option.

Manual Safety Pilot

The manual safety pilot (AKA SPK) has a pilot that is manually lighted and stays lit all the time. It’s very similar to the one you can find on your water heater. You can turn this burner on and off manually by just reaching into your fireplace and turning the control knob.

Remote Control

If using a match is too scary for you and the manual safety pilot is boring, then you can resort to a remote control start. Depending on the remote you choose, you will have the ability to control certain functions of the log set from your remote, such as the flame height and control. 

Additional Considerations

Pick Out Your Gas Log Materials

Most of the gas logs that we see are made from ceramic fiber or even refractory cement mixture to help withstand the high temperatures. The manufacturer may add steel reinforcement rods to increase the strength and to prevent bending or cracking. 

Refractory cement logs are extremely durable and tend to retain color and details much longer than ceramic fiber logs. 

Gas logs are usually cast from real tree samples or crafted from highly detailed molds that really help to give the logs an outstandingly realistic look. Refractory cement logs are usually hand-painted to match wood’s natural markings, pitting, and coloring. 

Components of a Gas Log Set

Your gas log set may come with more things than this list, but here is a list of 9 items that you’ll find in your gas log set. 

  1. Gas valve
  2. Pilot assembly
  3. Burner
  4. Steel grate
  5. Logs
  6. Sand or vermiculite
  7. Glowing embers
  8. Damper clamp
  9. Assembly accessories

Safety Tips for Gas Logs

Although gas log sets don’t contain any burning material, they do produce real fire and should be treated with the same safety considerations as wood-burning fireplaces. 

Follow these tips to stay safe when using your gas fireplace: 

  • Keep an approved fire extinguisher within easy reach of your fireplace
  • Install smoke detectors and carbon monoxide detectors
  • Never use gasoline or charcoal lighter fluid to start your fire
  • Keep flammable objects at least 3 feet from your fireplace

Schedule Your Inspection

Since fuel is consistent with gas appliances (leads to better combustion), and since gas appliances are much easier to handle, they represent the majority of new hearth appliance installations. However, these appliances need to be inspected and maintained just as much as wood stoves do.

Gas appliances need to be carefully adjusted to maintain efficiency and look. You have your furnace tuned up every year by your HVAC company, but did you know that you should have your gas logs tuned as well. 

You should have your gas fireplace inspected and serviced every year by a CSIA certified chimney sweep. A certified sweep doesn’t just specialize in wood-burning stoves. They also understand the basic characteristics of gas and the significant differences between natural gas and propane. 

If you want the most knowledgeable technician for gas appliances, you should look to hire a CSIA certified chimney sweep with the Installing & Troubleshooting Gas Hearth Appliances designation. Sweeps with this designation understand servicing and installing gas appliances, as well as appliance standards, combustion requirements, pipe sizing and installation, troubleshooting, carbon monoxide testing, and fuel conversion. 

At Patriot Chimney, we have two Certified Sweeps with this designation, so you’ll know that you and your family are safe.

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